Manhole head assembly for manhole column

ABSTRACT

A manhole head assembly for mounting a cover on a manhole column is disclosed. The manhole head assembly comprises a support member having a top portion made of a grindable material and a bottom portion shaped and sized to rest on the manhole column. The top and bottom portions form an inner shoulder sized and shaped to receive the cover. The manhole head assembly further comprises at least one removable spacer adapted to be disposed between the shoulder and the cover for adjusting the height thereof.

[0001] The present application claims the benefit of priority ofprovisional application No. 60/270,197 filed Feb. 22, 2001.

FIELD OF THE INVENTION

[0002] The present invention relates to manhole head assemblies formounting a cover on a manhole column. More particularly, it concerns amanhole head assembly which can easily be levelled to be flush with thesurface level of the surrounding pavement.

BACKGROUND OF THE INVENTION

[0003] Conventional manholes for draining water or allowing access to aperson having to work in the manhole, have many drawbacks, usuallycaused by the freezing and thawing of the ground surrounding the manholeassembly or by the vibrations caused by the passage of heavy vehiclesthereon. Indeed, in regions where varying temperature occurs, aseparation between the surrounding pavement and the manhole is oftenseen resulting in the projection of the manhole cover. This situationmay be troublesome for road maintenance during winter, i.e. for the useof snowplows. Another drawback is commonly seen with the use ofconventional manholes which comprise metallic parts. Indeed, the contactof these metallic parts with each other may be very noisy.

[0004] In the art, several adjustable manhole head assemblies have beenproposed to correct these problems. Examples of such manhole headassemblies are shown in U.S. Pat. Nos. 4,188,151; 4,187,647; 5,044,818;5,470,172; 5,564,855; 5,956,905; and 6,161,984.

[0005] While these manhole head assemblies have resulted in theadvancement within the present field, most of these prior art manholehead assemblies are, nevertheless very hard to rehabilitate.

[0006] There is thus presently a need for an improved manhole headassembly which will at least reduce one or more of these drawbacks.

SUMMARY OF THE INVENTION

[0007] It is therefore an object of the present invention to provide animproved manhole head assembly for mounting a cover on a manhole column.

[0008] In accordance with the invention, that object is achieved with amanhole head assembly for mounting a cover on a manhole column, themanhole head assembly comprising:

[0009] a support member having a top portion made of a grindablematerial and a bottom portion shaped and sized to rest on the manholecolumn, the portions forming an inner shoulder sized and shaped toreceive the cover; and

[0010] at least one removable spacer adapted to be disposed between theshoulder and the cover for adjusting the height thereof.

[0011] The present invention is also directed to a manhole columncomprising:

[0012] rims stacked over one another; and

[0013] a manhole head assembly for mounting a cover on the manholecolumn as defined above.

[0014] The present invention also proposes a method for levelling off amanhole column as defined above, the method comprising the steps of:

[0015] a) grinding down the top portion of the support memberapproximately to surface level of surrounding pavement; and

[0016] b) adjusting the height of the cover approximately to the levelof the top portion obtained in step a) by placing a desired number ofspacer between the shoulder and the cover.

[0017] A manhole head assembly for mounting a cover on the manholecolumn according to the present invention proposes innovative featuresthat makes it very easy to be levelled flush with the surroundingpavement. Furthermore, the head assembly of the present invention can bereadily and easily repaired on the spot.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention and its advantages will be more easilyunderstood after reading the following non-restrictive description of apreferred embodiment thereof, made with reference to the followingdrawings wherein:

[0019]FIG. 1 is an exploded cross-sectional side view of a manholecolumn with a manhole head assembly according to a preferred embodimentof the invention.

[0020]FIG. 2 is a perspective exploded view of the manhole head assemblyshown in FIG. 1.

[0021]FIG. 3 is another perspective exploded view of the manhole headassembly shown in FIG. 1.

[0022]FIG. 4 is a side view of the manhole column of FIG. 1, showing thecover and the spacers before installation on the manhole head assembly.

[0023]FIG. 5 is the same view as FIG. 4, showing now the cover installedon the manhole head assembly.

[0024]FIG. 6 is a side view of the manhole column of FIG. 1, showing thecover installed on the manhole head assembly in a sloped environment.

DESCRIPTION OF A PREFERRED EMBODIMENT

[0025] The present invention is directed to a manhole head assembly formounting a cover on a manhole column. It will be understood that themanhole head assembly of the present invention is suitable for use withmany types of manhole column know in the art. For instance, the manholehead assembly of the present invention is advantageously suitable foruse with manholes for sours and for electrical lines.

[0026] Referring to FIG. 1, a manhole column (10) according to apreferred embodiment of the invention is illustrated. The manhole column(10) comprises rims (12) stacked one over the other. In order to improvethe water tightness of the column (10) and to reduce harmful results ofvibrations, it may be advantageous to use rings (50) of impermeable andcushioning material adapted to be disposed between each rim (12).Although, such rings (50) may be made of any material known to oneskilled in the art, the present invention preferably contemplatesemploying rings (50) made of a material comprising epoxy, quartz andurethane. The manhole column (10) further comprises a manhole headassembly (14) for mounting a cover (16) on the same (14). For safetyreasons, one may find advantageous to lock the cover (16) to the manholehead assembly (14). In such a case, the use of bolts (4) as shown inFIG. 1, or any other type of locking mechanism known in the art willsuffice.

[0027] Now turning also to FIGS. 2 and 3, the manhole head assembly (14)comprises a support member (18) having a top portion (20) made of agrindable material and a bottom portion (22) shaped and sized to rest onthe upper rim (12) of the manhole column (10). The portions (20, 22)form an inner shoulder (24) sized and shaped to receive the cover (16).According to a preferred embodiment of the invention, the support member(18), the top (20) and bottom (22) portions have an annular shape.

[0028] The manhole head assembly (14) further comprises at least oneremovable spacer (26) adapted to be disposed between the shoulder (24)and the cover (16) for adjusting the height thereof. In other words, andas best viewed in FIG. 5, the level of the cover (16) can be adjusted tobe flush with the level of the support member (18) by adding or removingone or more spacers (26). Since the present invention contemplatesemploying a cover (16) made of any suitable material known in the art,it is thus preferable to use spacers (26) made of a cushioning materialsuch as rubber or a flexible polymer. Thanks to such an arrangement, thenoise induced by the contact of the cover (16) with the other parts ofthe manhole head assembly (14) is greatly reduced.

[0029] As mentioned above, the top portion (20) of the support member(22) is made of a material capable of surface grinding, and thatpreferably without cracking. According to a preferred embodiment of theinvention, such a material is preferably a polymeric cement, mostpreferably, the material is a polymeric cement comprising epoxy resinmixed with quartz of different sizes. In order to strengthen the supportmember (18), the polymeric cement is preferably reinforced with ametallic mesh. Furthermore, to facilitate the manufacture of the manholehead assembly (14) of the present invention, the support member (18), asa whole (i.e. top (20) and bottom (22) portions), is preferably made ofa polymeric cement.

[0030] As it can be appreciated by viewing FIGS. 4 and 5, a manhole headassembly (14) according to the present invention is easily flushlevelled with the surrounding pavement (2) because the top portion (20)of its support member (18) is made of a grindable material. This isachieved by simply removing, by surface grinding with a suitable tool, agiven thickness material. Therefore, when a manhole head assembly (14)is protruding with respect to the level of the surrounding pavement (2),for example as a result of frost, it can be simply levelled flush withthe pavement by first grinding the top portion (20) thereof and thenremoving one or more spacers (26), as required, so that the cover (16)and the top portion (20) of the assembly (14) be substantially flushwith the surrounding pavement (2).

[0031] When viewing FIGS. 4 and 5, it is clear that the given thicknessmaterial removed from the top portion (20) has a substantially uniformthickness in order to level flush the manhole head assembly (14) withthe surrounding pavement (2). In such a case, the spacers (26) have alsoan uniform thickness. However, when the surrounding pavement (2) is in asloped environment, as shown in FIG. 6, the material to be removed mayhave a non-uniform thickness. In that case, it may be advantageous toprovide one or more spacers (26 a) with non-uniform thickness so as tocompensate for the sloping surface.

[0032] In this connection and according to another aspect of theinvention, a method for levelling off a manhole column (10) as definedabove is proposed. The method comprises the steps of:

[0033] a) grinding down the top portion (20) of the support member (18)approximately to surface level of surrounding pavement (2); and

[0034] b) adjusting the height of the cover (16) approximately to thelevel of the top portion (20) obtained in step a) by placing a desirednumber of spacer (26) between the shoulder (24) and the cover (16).

[0035] To sum up, the manhole head assembly (14) according to thepreferred embodiment described above is believed to overcome manydrawbacks of the prior art manhole head assemblies, for example:

[0036] it can be very easily levelled flush with the surroundingpavement (2),

[0037] the polymeric cement used for the support member (18), and also,if desired, for the annular rims (12) of the manhole column (10), isresistant to saline solutions, and is capable of absorbing vibrations;

[0038] it is not noisy, because there are no metallic parts in contactwith each other;

[0039] the spacers, which act as a cushioning material, absorb a greatpart of the noise; and

[0040] because of the material used (viz. a grindable material), themanhole head assembly (14) can be readily and easily repaired on thespot.

[0041] Although the present invention has been explained hereinabove byway of a preferred embodiment thereof, it should be understood that theinvention is not limited to this precise embodiment and that variouschanges and modifications may be effected therein without departing fromthe scope or spirit of the invention.

What is claimed is:
 1. A manhole head assembly for mounting a cover on amanhole column, the manhole head assembly comprising: a support memberhaving a top portion made of a grindable material and a bottom portionshaped and sized to rest on the manhole column, the portions forming aninner shoulder sized and shaped to receive the cover; and at least oneremovable spacer adapted to be disposed between the shoulder and thecover for adjusting the height thereof.
 2. A manhole head assemblyaccording to claim 1, wherein the support member and the top and bottomportions have an annular shape.
 3. A manhole head assembly according toclaim 1, wherein the material is a polymeric cement.
 4. A manhole headassembly according to claim 3, wherein the polymeric cement comprisesepoxy resin mixed with quartz of different sizes.
 5. A manhole headassembly according to claim 4, wherein the polymeric cement furthercomprises a metallic mesh.
 6. A manhole head assembly according to claim1, wherein the support member comprises locking means for locking thecover with respect to the support member.
 7. A manhole head assemblyaccording to claim 1, wherein the spacer is made of a cushioningmaterial chosen for the group consisting of rubber and flexible polymer.8. A manhole column comprising: rims stacked over one another; and amanhole head assembly for mounting a cover on the manhole column, themanhole head assembly comprising: a support member having a top portionmade of a grindable material and a bottom portion shaped and sized torest on the upper rim of the manhole column, the portions forming aninner shoulder sized and shaped to receive the cover; and at least oneremovable spacer adapted to be disposed between the shoulder and thecover for adjusting the height thereof.
 9. A manhole column according toclaim 8, wherein the rims, the support member and the top and bottomportions have an annular shape.
 10. A manhole column according to claim9, further comprising rings made of impermeable and cushioning material,adapted to be disposed between the rims.
 11. Method for levelling off amanhole column as defined in claim 8, the method comprising the stepsof: a) grinding down the top portion of the support member approximatelyto surface level of surrounding pavement; and b) adjusting the height ofthe cover approximately to the level of the top portion obtained in stepa) by placing a desired number of spacer between the shoulder and thecover.